The present invention relates to a manually actuated control device for mechanically regulating the speed of hydraulic pumps on hydraulically driven vehicles.
On hydraulically driven vehicles, such as various types of rollers, progressive adjustment of the drive device for forward and reverse motion is necessary. Other applications for progressive control are flow restrictor valves, throttle control on combustion engines, various control connections which may be mechanical, hydraulic or pneumatic and designed for vehicles, construction machines, boats or aircraft, etc. where control should be progressive.
A hydraulic motor usually operates at fixed output power. The supply of hydraulic power to the motor must therefore be controlled so that starting and braking of the motor can be achieved smoothly. It is previously known that with the aid of a slot cut into an operating disc it is possible to produce a movement in, for example, an operating cable interacting with the slot which is a non-linear function of the movement of the pertinent control lever or pedal. This method of achieving non-linear movement in an operating cable is comparatively complicated, however.